PT Cruiser L4-2.4L Turbo VIN G (2004)
Road Temperature Sensor: Testing and Inspection
AMBIENT TEMP SENSOR
The thermometer function is supported by the ambient temperature sensor, a wiring circuit, and the compass/temperature display unit.
If the display shows OC (-49 °F (-45 °C) or SC (140 °F (60 °C), there is an OPEN or SHORT CIRCUIT and it must be repaired before the VFD can
be tested.
The ambient temperature sensor circuit can also be diagnosed using the following Sensor Test, and Sensor Circuit Test. If the temperature sensor and
circuit are confirmed to be OK, but the temperature display is inoperative or incorrect, replace the compass/temperature display.
Fig.4 Battery Negative Cable Remove/Install
Sensor Testing
1. Turn the ignition switch to the OFF position. Disconnect and isolate the battery negative cable. Disconnect the ambient temperature sensor wire
harness connector.
2. Measure the resistance of the ambient temperature sensor. At -40 °C (-40 °F), the sensor resistance is 336 kilohms. At 55 °C (140 °F), the sensor
resistance is 2.488 kilohms. The sensor resistance should read between these two values. If OK, refer to Sensor Circuit Test in the Diagnosis and
Testing. If not OK, replace the faulty ambient temperature sensor.
Sensor Circuit Testing
1. Turn the ignition switch to the OFF position. Disconnect and isolate the battery negative cable. Disconnect the ambient temperature sensor wire
harness connector and the compass/temperature display unit wire harness connector.
2. Connect a jumper wire between the two terminals in the body half of the ambient temperature sensor wire harness connector.
3. Check for continuity between the sensor return circuit and the ambient temperature sensor signal circuit cavities of the compass/temperature
display unit wire harness connector. There should be continuity. If OK, go to Step 4. If not OK, repair the open sensor return circuit or ambient
temperature sensor signal circuit to the ambient temperature sensor as required.
4. Remove the jumper wire from the body half of the ambient temperature sensor wire harness connector. Check for continuity between the sensor
return circuit cavity of the compass/temperature display unit wire harness connector and a good ground. There should be no continuity. If OK, go
to Step 5. If not OK, repair the shorted sensor return circuit as required.
5. Check for continuity between the ambient temperature sensor signal circuit cavity of the compass/temperature display unit wire harness connector
and a good ground. There should be no continuity If OK, replace the compass/temperature display unit. If not OK, repair the shorted ambient
temperature sensor signal circuit as required.
